Cardiology Division, Department of Internal Medicine, Yonsei University Wonju College of Medicine, Wonju, South Korea.
Int J Cardiol. 2013 Oct 3;168(3):2008-13. doi: 10.1016/j.ijcard.2012.12.086. Epub 2013 Jan 19.
Q waves on a 12-lead electrocardiography (ECG) are considered to be classic hallmarks of prior myocardial infarction. However, one study suggested that the fragmented QRS complex (fQRS) on ECG is a highly sensitive and specific marker of myocardial scarring on a nuclear stress test. The study aimed to investigate the diagnostic accuracy of fragmented QRS complexes compared with Q waves for myocardial injury detected by delayed contrast-enhanced cardiovascular magnetic resonance imaging (DE-CMRI) in subjects with acute myocardial infarction.
Electrocardiograms of 190 subjects with myocardial infarction who underwent DE-CMR were analyzed. fQRS was defined by the presence of an additional R wave (R″), or notching of the S wave, or more than one R' in two contiguous leads.
Delayed enhancement was observed in 180 (94.7%) patients. Transmural enhancement was noted in 78 (43.3%) and subendocardial enhancement in 102 (56.7%) patients. The sensitivity and specificity of Q waved and fQRS for diagnosing delayed enhancement were 59.4% vs. 66.7% and 90.0% vs. 40.0%. The area under the receiver-operator characteristics curve of delayed enhancement was 0.75 for Q waves and 0.53 for fQRS (p=0.04). The areas under the ROC curves of the transmurality of delayed enhancement were 0.44 for fQRS and 0.58 for Q waves (p=0.73).
fQRS has poor accuracy for the detection of myocardial injury compared with Q waves. fQRS and Q waves are not valuable tools for the diagnosis transmural irreversible myocardial injury in acute myocardial infarction.
12 导联心电图（ECG）上的 Q 波被认为是既往心肌梗死的经典标志。然而，一项研究表明，心电图上的碎裂 QRS 复合体（fQRS）是核应激试验中心肌瘢痕的高度敏感和特异标志物。本研究旨在探讨 fQRS 与 Q 波相比，在检测急性心肌梗死后延迟对比增强心血管磁共振成像（DE-CMRI）检测到的心肌损伤中的诊断准确性。
分析了 190 例接受 DE-CMR 的心肌梗死患者的心电图。fQRS 定义为在两个连续导联中存在额外的 R 波（R″）、S 波切迹或一个以上的 R'。
180 例（94.7%）患者出现延迟增强。78 例（43.3%）患者出现透壁增强，102 例（56.7%）患者出现心内膜下增强。Q 波和 fQRS 诊断延迟增强的敏感性和特异性分别为 59.4%和 66.7%和 90.0%和 40.0%。Q 波和 fQRS 延迟增强的受试者工作特征曲线下面积分别为 0.75 和 0.53（p=0.04）。fQRS 和 Q 波延迟增强透壁性的 ROC 曲线下面积分别为 0.44 和 0.58（p=0.73）。
与 Q 波相比，fQRS 检测心肌损伤的准确性较差。fQRS 和 Q 波对于诊断急性心肌梗死后透壁性不可逆心肌损伤不是有价值的工具。
